1. Field of the Invention
The present invention relates to a human apoptosis inhibitory protein, and a gene encoding the protein and the cDNA thereof. More specifically, the present invention relates to the genetic materials which are useful for the elucidation of the onset mechanism of various apoptic diseases such as human spinal muscular atropy, the diagnosis of the risk of the onset thereof, and the prevention of the onset thereof. In addition, the materials are useful for the development of clinical techniques and pharmaceutical agents for the amelioration and therapeutic treatment of the diseases.
2. Description of the Related Art
Apoptosis is a programmed cellular death, involving observed phenomena such as the loss of cellular contact with surrounding cells, cytoplasmic condensation, chromatin condensation and nuclear condensation with relation to endonuclease activity, nuclear fragmentation, membrane-enveloped spherical microbodies, the phagocytosis of spherical microbodies with adjacent macrophages or epithelial cells, or the fragmentation of the DNA nucleosome unit into DNAs of 180 to 200 bp due to endonuclease activity. It is suggested that apoptosis is a phagocytic mechanism for the final fragment of an apoptic somatic cell under such observed phenomena by adjacent cells (see for example Immunology Today 7: 115-119, 1986; Science 245:301-305, 1989).
As an apoptosis inhibitory gene, for example, gene bcl-2 has been known. The gene bcl-2, one of oncogenes discovered in 1985 in alveolar B cytoma, is highly expressed in the immune system and nervous system, and it is believed that the expression product of the gene serves to maintain the homeostasis of the human immune functions and neuronal functions, by inhibiting the apoptosis of the cells involved. Additionally because the bcl-2 is expressed in a diversified range in fetuses in particular, the gene is believed to play a significant role in morphological formation during ontogenesis.
Meanwhile, the present inventors have isolated the gene of a neuronal apoptosis inhibitory protein (NAIP) from the human chromosome 5q13.1 region as an etiological gene of a familial hereditary disease spinal muscular atropy (SMA) (Roy et al., Cell 80: 167-178, 1995), and have filed a patent application (PCT/CA95/00581). More specifically, it is supposed that the mutation of the NAIP gene or the decrease of the copy number thereof might cause the apoptosis of spinal neuron, which is an etiology of the SMA onset. It is apparently demonstrated that by introducing the NAIP gene into various cultured cells to give apoptosis-inducing stimulation to the cells, the death of the cells is inhibited (Liston et al., Nature 379: 349-353, 1996), which indicates that NAIP plays a role of an apoptosis inhibitory factor for not only neuronal cells but also overall somatic cells.
The present inventors have further promoted the analysis of the NAIP gene, and they have successfully achieved to clone the full length of cDNA of NAIP gene and to identify the protein encoded in the cDNA.
It is an object of the present invention to provide the cDNA of NAIP gene thus found by the present inventors, genetic materials with relation to the cDNA and the expression products thereof and the like in industrially applicable forms.
An invention provided by the present application is a human apoptosis inhibitory protein which comprises the amino acid sequence of SQ ID No:1, or an amino acid sequence with deletion, substitution or addition of a single or plural amino acids in SQ ID No:1.
Another invention is a human apoptosis inhibitory protein comprising the amino acid sequence of SQ ID No:3, or an amino acid sequence with deletion, substitution or addition of a single or plural amino acids in SQ ID No:3.
Other inventions are a human gene encoding the human apoptosis inhibitory proteins, cDNAs of said human gene which comprises at least the nucleotide sequence for the coding region of SQ ID No:2 or NO:4.
Still additionally, inventions of this application are an antibody against the human apoptosis inhibitory proteins, a non-human animal gene to which the above cDNAs are hybridized, recombinant vector carrying the cDNAs or a partial sequence thereof, a DNA probe comprising a partial sequence of the cDNAs, and a set of PCR primer corresponding to partial sequences of the cDNAs.
The present inventions will now be described below in more detail with reference to embodiments.